Conventionally a ratio of blood pressures measured on a lower limb and an upper limb (ankle-brachial blood pressure index) has been generally used as an indicator of a vascular disease such as arteriosclerosis. As an ankle-brachial blood pressure index, for example, a ratio of systolic blood pressures measured on a brachium and an ankle (ABI) and a ratio of systolic blood pressures measured on a brachium and a toe (TBI) have been known. For example, in the case of (lower limb blood pressure/upper limb blood pressure)≦0.9, the indicator is used to indicate the possibility of arteriostenosis on the lower limb.
However, when arteriosclerosis develops through the whole body, an ankle-brachial blood pressure index may present a normal value. Therefore, an ankle-brachial blood pressure index is proposed which is used as a more accurate indicator in combination with a pulse wave propagation velocity or pulse wave velocity (PWV) (for example, see Japanese Patent Laid-Open No. 2000-316821).
However, in order to discriminate an arterial disease, it is necessary to evaluate blood pressure values itself as well as a blood pressure index such as ABI. For example, when a difference in blood pressure value between right and left brachia is 20 mmHg or higher, there is a possibility of hemodynamic disorder on the brachium having a lower blood pressure. In conventional devices for evaluating ABI, the principal object is to present a ratio of blood pressure values. Measured blood pressure values have not been presented using a method for easily knowing respective measured blood pressure values or intuitively knowing the relationship with other measurement values.